1. Field of the Invention
The present invention is directed to a drive unit, particularly for a revolving door, with an electronically commutated multipole motor. The invention is further directed to a revolving door with a drive unit comprising an electronically commutated multipole motor.
2. Description of the Related Art
DE 10 2006 015 065 A1 describes a drive unit with an electronically commutated multipole motor, also known as a torque motor. The torque is generally achieved by a stationary stator that transmits the torque directly to the rotor via the air gap. This drive concept dispenses with mechanical transmission elements such as gearboxes and, accordingly, also with the inaccuracies caused by the mechanics of gearboxes. Further, the multipole motor offers a virtually wear-free and maintenance-free operation. The multipole motor has a stator part, which is flanged to a structural component part of a machine, for example. Further, the multipole motor has a rotor which is annularly constructed and is rotatably received at the stator.
DE 10 2010 024 108 A1 shows a drive unit for a revolving door constructed as an electronically commutated multipole motor. The multipole motor has a disk-shaped, flat configuration and is described as having a build height of less than 80 mm. Accordingly, the multipole motor is suitable in a particularly advantageous manner for driving the turnstile of the revolving door, particularly since no gearbox is necessary for transmitting the rotational movement of the rotor part of the multipole motor to the turnstile.
Multipole motors have a quantity of coil elements and a quantity of magnet elements. The coil elements are preferably arranged at the stator part and the magnet elements are preferably arranged at the rotor part. When the coil elements are supplied with current under electronic commutation, a magnetic field surrounding a drive axis is achieved by successively energizing the coil elements, resulting in a rotational movement of the rotor part at the stator part. The stator part is often formed of housing components in which the rotor part rotates concentric to the axis of symmetry of the housing. To improve the magnetic field circuit, the coil elements have ferrite cores on which wound components are arranged. The magnet elements can also be received by ferritic elements which likewise optimize the magnetic field circuit. The ferritic elements for receiving the wound components of the coil elements and magnet elements are usually arranged at the housing components of the multipole motor. This results in a complicated construction which often comprises castings and component parts which are machined by cutting and is designed so as to achieve the best possible sealing of the area between the rotor part and the stator part. There is also the drawback that multipole motors are frequently enclosed by housings from which an output shaft projects, which must likewise be sealed. The basic construction of motors of this kind is essentially longitudinally cylindrical, and an armature rotates along the axis of symmetry of the longitudinally cylindrical stator housing.